Hot air furnace



NOV; 1941- J. 0. JOHNSTON 2,263,732

,, HOT-AIR FURNACE Filed July 24, 1940 2 Sheets-Sheet l gwum J Z7. Ja/nzzsfazz NOV. 25, 1941. J o JOHNSTON 2,263,732

HOT A'IR FURNACE I I Filed July 24, 1940 Sheets-Sheet 2 'FE W J A] Jaimazan I I a installation at low cost.

Patented Nov. 25, 1941 FFICE HOT AIR FURNACE ass 0. Johnston.

St. Petersburg, Fla,, assignor to City Fuel Oil and Coal Company, St. Petersburg; Flax, acorporation of Florida Application July 24, 1940, Serial No. 347,315

This invention relates generally-to hot airsfurnaces; and more particularly to compact airheating units adapted to heat and discharge Warm filtered air directly into small houses or apartmen-ts. I 1 i The main object of the invention is to provide a compact heater of great efficiency in comparison to its size and ofsuch simplicity in con struction as to adapt it for manufacture and Other objects of the invention will become apparent as the detailed description thereof proneeds.

In the drawings:

Fig. 1 is avertical section of the hot air heater forming the subject matter of this application. the section being taken on the line i-'-| of Fig. 2.;

Fig. 2 is'a central vertical section taken substantially on the line 2-2 of Fig. 1; some ofthe lower parts being shown in elevation;

Fig. 3 is a horizontal sectiontaken on the line 3-3 of Fig. 2; i

Fig. 4 is a horizontal swtion taken on the line 4-4 of Fig. 2; and i Fig. 5 is a fragmentary vertical section taken on theiine 5-5 of Fig. 4.

As shown in the drawings, this air conditioner comprises a casing of suitable sheet material. designated generally by the reference numeral 6. Angle iron standards I, suitably cross connected to each other form the supporting framework for the casing and the other members of the furnace. The front wall 8of the casing is cut to form a circular aperture 9 in which a closure plate Iii fits snugly to form a mount for the burner II, the specific details of which form no part of the present invention.

A cylindrical heating chamber or primary heat exchanger l2, of substantially the same diameter as the aperture 9, is suitably secured with gastight fit to the front wall 8, and extends horizontally from said aperture toward the rear wall It of the casing. The rear end of the chamber I2 is closed by a plate 14 and is spaced from the wall I 3 to form an air conducting passageway IS. A strap It has its opposite ends bent to form the legs I l and I8 and is secured to the plate It with the ends of the legs I! and it sprung into the corners of the adjacent angle iron standards I of the framework.

As shown clearly in Figs. 1 and 2, the heating chamber l2 has its cylindrical outer surface spaced inwardly from the side walls l9 and of the casing 6,

passageway l5, symmetrically arranged conduits in order to form, along with the 2 Claims. (01. 126-110) for air directed from the lower. end of the casing against the said chamber 12. A frusto-pyramidal partition or lower deflector members 2 l is arranged in the casing directly below the chamber I2, and is provided with a flanged aperture 22 adapted to be connected by a flexible connector 23 to the discharge outlet 24 of a blowere25.

The partition 2|. forms the topof a chamber 26 in which the blower 25 is mounted for operation by the motor 21. In order to. reduce vibration to a minimum, the blower supporting standards 28 and 29 are mounted at thcinlower ends on springy'straps 30 and 3|, respectively, which extend across, the casingi between the walls 19v and 2d. The opposite ends of these straps are secured to vibration. dampcners 32. supported by shelves 33 projecting inwardlyfrom the framework, of the furnace.

The standard 29 includes a pair of uprights 34 and 35 extending vertically up from the, strap 31. A cross-bar .36'connects the tops of. the-uprights 34 and 35 and carries a hearing at itscenter to support one end of the blower axle 38. The structural details of the standard 28 are not shown in the drawings, since they are the same as the details of the standard 2.9. The axle 33 projects beyond the blower supporting standard 28. to receive a pulley 39 connected for rotation by a belt 40 driven by the'motor 21, which is also suitably mounted on the straps .30 and 3| to reduce vibration, as much aspossible. An air filter 4|, detachably mounted on angle ironsvild,

. closes the bottom of the blower. chamber .26..

A short flue 43 connects the primary heating chamber I 2 to a secondary heat exchanger or heater 44; and a discharge flue 45 extends from the upper end of the heater-44 through the front wall 8 of the furnace casing. A flange 45' on the outer end of the flue 45 is adapted to connect to such piping as may be found necessary to conduct the products of combustion away from the rooms or apartments being heated by the furnace.

As shown in Figs. 2 and 4, the secondary heater 44 is supported by the flues 43 and 45, with its top, bottom and side walls spaced apart from the adjacent parts of the casing 6 and primary heating chamber I 2 in order to ensure a secondary heating of the air previously heated by contact with the surface of the chamber l2. To increase the air heating surface area of the secondary heater 44, pipes 48 and 49 extend through the top 50 and bottom 5| of the heater 44 and form additional previously heated by chamber l2. Any desired heating passageways for the air number of these pipes may be used to superheat the air as it is forced upwardly around and across the primary heater l2 toward the register formed by the apertured top 41 of the furnace casing. In order to deflect the air flowing past the primary heater l2 inwardly across the bottom 5| of the secondary heater 44 and around the pipe 43, angular baflies or upper deflector members 52 and 53 are secured to the sides l9 and 2d of the furnace casing to project inwardly between the top of primary heater l2 When the burner H the chamber l2 becomes heated and, with the products of combustion, escapes through the short pipe 43 into the secondary heater 44 and around the pipes 48 and 49 to the discharge flue 45 and its connector 45. The air drawn through the filter 4| by the blower 25 is forced around and across the primary heater l2 and across the bot-, tom of the secondary heater 44 by the vbaflles 52 and 53 to be superheated by contact with the hot surfaces of the heater 44 and pipes 48 and 49 as it flows or is forced toward the register 41. 7 While the top, bottom and sides ofthe furnace casing 6 are illustrated as integrally connected to each other, it will be readily understood that these members may be detachabll connected to each other and provided with whatever means may be found necessary or desirable to facilitate assembly, or provide access to the various parts for repair or renewal.

What I claim is:

1. In a hot air furnace of the type comprising an open lower end and a top apertured to form a register, a cylindrical combustion chamber extending horizontally as a primary heat exchanger, a blower adapted to direct a flow of air about the said primary heat exchanger, a secondary heat exchanger mounted vertically said secondary heat exchanger having openings extending vertically through the said secondary heat exchanger toward the said register; the 1mand secondary heater 44.

is ignited, the air within above the said primary heat exchanger and the T provement which comprises an inverted frustok pyramidal partition dividing the said furnace into upper and lower chambers and having an air inlet at its downwardly directed apex and with the outlet of the said blower coincident with said inlet, and the said inverted frustropyramidal partition positioned in such a manner as to direct the air from the said blower around the lower surface of the said primary heat exchanger and around the end of the said cylindrical primary heat exchanger, deflector members projecting into the space between the said primary and secondary heat exchanger, the said deflector members adapted to cooperate with the said frustro-pyramidal partition in such a manner as to direct the said flowing air circumferentially around opposite semi-circular surfaces of the said cylindrical combustion chamber, each of the said deflector members having an upper and lower side and the said lower side connected substantially at an angle to the said upper side whereby the flowing air from the blower aforesaid is retarded and directed by the lower side of the said deflector members around the upper surface of the primary heat exchanger and a portion of the said flowing air is directed by the said lower side along the bottom wall of the secondary heat exchanger toward the lower ends of the aforementioned openings provided in the said secondary heat exchanger and Whereby the remaining portion of the said flowing air is directed by the said upper side of the said deflector members around the said secondary heat exchanger toward the said register.

2. In a hot air furnace of the type comprising an open lower end and a top apertured to form a register, a cylindrical combustion chamber extending horizontally as a primary heat exchanger, a blower adapted to direct a flow of air about the said primary heat exchanger, a secondary heat exchanger mounted vertically above the said primary heat exchanger and the said secondary heat exchanger having openings extending vertically throughthe said secondary heat exchanger toward the said register; the improvement which comprises lower deflector members adapted to direct the air from the said blower around the lower surface of the said primary heat exchanger, upper deflector members projecting into the space between the said primary and secondary heat exchanger, the said upper and lower deflector members adapted to direct the said flowing air from the said blower circumferentially around opposite semi-circular surfaces of the said cylindrical combustion chamber and the upper deflector members positioned in such a manner as to retard the flowing air from the blower aforesaid and direct the said flowing air toward the lower ends of the said openings provided in the said secondary heat exchanger and toward the said register.

JAMES O. JOHNSTON. 

